Portable motor knife grinder



Feb. 22, 193s. J, R, EADIE O 2,109,107

' PORTABLE MOTOR KNIFE GRINDER Filed April 26, 1937 frm/enfer. John R. Edo/fe.

Patented F eb. 22, 1938 UNITED STATES rATET orifice 8 Claims.

The principal objects of this invention are to facilitate the sharpening of knives such as used on dry milk machines or other mechanisms where an elongated blade is employed requiring frequent sharpening and to provide a form of device for this purpose which will be readily adjustable and capable of easy manipulation.

The principal feature of the invention resides in the novel construction and arrangement of mounted in a frame which is provided with means to engage the blade to be sharpened in guiding contact with the fiat face of the grinding wheel presented in bevel grinding relation to the blade. In the drawing, Figure l is a perspective view of a device constructed in accordance with the present invention.

Figure 2 is a miniature diagrammatic view showing the blade to be sharpened arranged in its normal operating position.

Figure 3 is a more enlarged diagrammatic view of the arrangement shown in Figure 2, showing the blade swung outwardly and the manner in which my grinding device co-operates therewith.

For purposes of illustration I have chosen to show and describe my improved sharpening device in connection with the drum-scrapingknife of a dry milk machine, which, in order to obtain the best results, requires frequent sharpening,

but I am aware that my invention has wider fields of application an-d may be applied to advantage in the sharpening of elongated blades or knives employed in different types of machines including veneer-cutting machines or drum freezing machines.

Referring to the illustrated construction, I have shown a light frame A formed of a length of strip steel having parallelly-spaced side portions I disposed in a horizontal plane and connected at the rearward end by the portio-n 2 disposed in a Vertical plane and having a reinforcing strip 2' secured thereto, the forward end of the side members I being turned angularly upward in the form of a guide connected by a cross member 3.

A pair of looped metal strips 4 are secured to the side members I of the frame and extend angularly upward and forward having their intermediate portions curved forwardly and downwardly and connected by a cross portion or strip 5 which is disposed substantially in the plane of disposition of the guide portions I', so that they collectively present guide surfaces adapted to engage the surface of the blade E which is to be parts whereby a motor-driven grinder is slidably (Cl. 51-1'l'3) sharpened, thereby arranging the frame A in prev determined angular relation to the blade.

A frame B formed of a strip of metal bent to form the side guide portions G and connecting end portion 'I is slidably arranged within the frame A, the portions 6 beingparallelly disposed and arranged in a horizontal plane, while the portion 'I is disposed in a vertical plane'and reinforced by the metal strip 'I'.

A strip l! of metal is bent into semi-circular form intermediate of its length and the ends thereof are connected to the forward ends of the slidable frame B and the extremities thereof are bent or arranged to slidably engage the side portions I of the frameA in sliding and guiding contact.

Additional guide members 9 in the form of strips of metal are secured to the side members Ii of the frame B at the top and bottom to snugly engage the topI and bottom surfaces of the side portions I in sliding contact.

A strip of metal Ill is secured across the side members 6 of the slidable frame B intermediate of the length thereof and the end portions overlap the side portions I of the frame A in supporting and guiding contact, while the intermediate portion is curved downwardly and rearwardly in semi-circular form to provide a support for a grinding motor C so that its axis is disposed in a downwardly and forwardly sloping direction.

A grinding wheel D is mounted on the forward end of the motor shaft II by means of a sleeve I2 so that the flat forward end face of the grinding wheel is unobstructed for diametrical grinding contact with the edge of the blade E. The angular mounting of the motor is such that the flat grinding face of the grinding wheel D is disposed in a plane angularly intersecting the plane of disposition of the guide elements I and 5 so that it will be presented at the desired angle or bevel to the edge of the blade as determined by the surface contact of the guide portions I and E with the blade and the upper edge extremity of the portion 5 may advantageously engage the underside of the blade-supporting bar E in guiding contact as the entire device is moved manually longitudinally of the blade E.

A spindle I3 is threaded centrally through the frame portion 2 and reinforcing portion 2 with the inner end thereof rotatably engaging the portions 'I and l of the slidable frame and confined against axial displacement, a hand wheel I4 being carried at the outer end of the spindle to rotate the same so that the frame B with the motor and grinder may be accurately adjusted toward or away from the blade in relation to the guide portions l' and 5. A coiled compression spring I5 is here shown arranged between the hand wheel and the frame portion 2' to frictionally retain the spindle in its adjusted position.

The semi-circular curvature oi the guide member 8 permits the grinding wheel to be accommodated between the end extremities of the slid-A able frame members 6, while at the same time ensuring a firm connection therebetween.

The device is of a simple and inexpensive nature, but will greatly facilitate the grinding of elongated blade members.

What I claim as my invention is:-

1. A portable blade-grinding device comprising intertting frame members connected to slide relative to each other in a common plane, one of said frame members having extension guide means disposed in a plane angularly intersecting` the aforesaid plane and adapted to engage in guiding contact with a side surface of the blade to be ground, a motor driven grinding wheel presenting ar substantially at grinding face, means for mounting said motor driven grinding Wheel in the other of said frames with its flat outer surface disposed in a plane intersecting the said second mentioned plane for diametrical bevelgrinding Contact with the edge of the blade, and means for relatively adjusting said frames.

2. vMeans as claimed in claim 1 in which said frames includespaced-apart guide portions between which the grinding wheel is rotatably mounted, said guide portions being disposed in a substantially common plane arranged in acute angular relation to the said grinding face of the wheel.

3. A portable blade-grinding device comprising inter-fitting frame members slidably connected and disposed in a common plane, one of said frame members having guide extensions disposed in a plane angularly intersecting the aforesaid plane for guiding contact with the blade to be ground, a grinding wheel rotatably mounted in the other of said framesy presenting a flat outer surface for diametrical bevel-grinding contact with the edge of the blade, the axis of said grinding wheel being disposed in a plane angularly intersecting the plane of disposition of said frame and the plane of disposition of said blade-engaging guide means, means for slidably adjusting said grinder-carrying frame in the other frame, and means for rotating said grinding wheel.

4. A portable blade-grinding device comprising a pair of frame members formed of strips of metal bent into substantial U-shape form having the side portions arranged in parallel sliding contact, the end extremities of one of said frames being turned angularly upward to engage the blade in guiding contact, threaded adjusting means interposed between the transverse portions of said U-shaped frames: for slidably adjusting the same, and a motor grinder supported between the side portions ofthe other of said U-shaped frames, said motor grinder including a grinding wheel having aside grinding face, the angular relation of said blade-guided portions of the frame and said side grinding face being such that the said motor grinder will be positioned with said side-grinding face in grinding contact with the edge portion of the blade.

5. A device as claimed in claim 4, in which guide members are secured tothe side members of the first-mentioned U-shaped frame intermediate of the length thereof and are looped above the grinding element and extend forwardly and downwardly and carry a guide portion, for guiding contact with the blade.

6. A device as claimed in claim 4 in which a strip of metal is secured in bridging relation to the end extremities of the second-mentioned U-shaped frame and engages the side members of the first-mentioned frame in guiding contact, the intermediate portion of said metal strip being disposed in semi-circular formation to provide accommodation of the grinding wheel between the end extremities of the second-mentioned frame.

7. A device as claimed in claim 4 in which a strip of metal extends transversely of the frames intermediate of their length on which the motor grinder unit is supported, said metal strip being secured at its ends to the side portions of one of said frames and engaging the side portions of the other frame in guiding and support contact.

8. A portable grinding device expressly forI the bevelled grinding of a wide flat blade comprising, a frame, a motor mounted on said frame, a grinding wheel mounted on the shaft of said mo-tor and having a flat grinding face, and means extending angularly from said frame in a plane intersecting the axis of said grinding wheel adapted to engage in sliding Contact with the Wide flat face of the blade to hold the flat grinding face of said grinding wheel in bevelled grinding relation to said blade.

JOHN R. EADIE?. 

